Apparatus for slitting ribbon cables



Aprll 18, 1967 F. FAUCONNIERE APPARATUS FOR SLITTING RIBBON CABLES 4 Sheets-Sheet 1 Filed Oct. 4, 1965 FIG. 1

INVENTOR. FELICE FAUCONNIERE ATTORN EYS April 1967 F. FAUCONNIERE 3,314,321

APPARATUS FOR SLITTING RIBBON vCABLES Filed Oct. 4, 1965 4 Sheets-Sheet Z Y 34 FIG. 3

INVENTOR. FELICE FAUCONNIERE BY W aw,

ATTORNEYS April 18, 1967 F. FAUCONNIERE APPARATUS FOR SLITTING RIBBON CABLES 4 Sheets-Sheet 5 Filed Oct. 4, 1965 INVENTOR. FELICE FAUCONNIERE ATTORNEYS April 18, 1967 F. FAUCONNIERE 3, 4,

APPARATUS FOR SLITTING RIBBON CABLES Filed Oct. 4, 1965 4 Sheets-Sheet 4 /4| Q I F 72 FIG. 9 B

INVENTOR. FELI CE FAU CONNIERE BY WMM 5M? ATTORNEYS United States Patent 3,314,321 APPARATUS FOR SLITTING RIBBON CABLES Felice Fauconniere, Chesapeake City, Md. 21915 Filed Oct. 4, 1965, Ser. No. 492,705 12 Claims. (Cl. 83-4) The present invention relates to a new and improved tool for expeditiously and efficiently slitting the ends of multi-strand cables of the type used in the wiring of switchboards, computers and the like.

To facilitate wiring of sophisticated circuits and to prevent undue proliferation of loose wires, miniature electrical conductors have been manufactured in flat ribbons comprised of multi-colored, coded insulation for the purposes of facilitating wiring. While these ribbon cables have been provided for neat wiring of complicated circuitry, the requisite physical separation of individual conductors, necessary for their connection with other circuit elements, has in many instances been a relatively tedious and time consuming operation. The necessary separations have been effected by carefully inserting cutters and knives between the individual insulated conductor wires of the cable to separate one from the other without impairing the integrity of the insulating sheaths enveloping each of the individual wires. A typical method of accomplishing this separation has involved the employment of a razor blade to separate the individual conductors. As may be readily understood, this has not been entirely satisfactory in terms of efficiency and reliability, and has been quite a slow process, i.e., 1100 separations per hour (lo-conductor ribbons) with approximately percent total rejects due to wire damage.

The present invention provides a simple tool for uni formly separating the ends of a ribbon cable in a highly efiicient, expeditious, and most reliable manner. For example, it is now possible to effect 8800 separations per hour (-conductor ribbons) with a complete absence of rejects due to wire damage. In one mode of operation of the new and improved tool, the separations of adjacent wires of the ribbon are effected along uniform lengths so that the ends of the cuts define a straight axis of bending perpendicular to the longitudinal axis of the ribbon. With a straight axis of bending, the individual conductors may easily be bent out of the plane of the ribbon. Additionally, the present invention provides means for separating the components of a ribbon cable along different length cuts, the ends of which are definitive of of an angular axis of bending which is at an angle to the longitudinal axis of the ribbon and is readily accommodative of the parallel bending of the conductors in the plane of the ribbon.

Specifically, the new tool includes an opposed rotatable gang cutter and a ribbon cable supporting drum which form a slitting nip. The apparatus also includes means for guiding the end of a cable through the slitting nip in a predetermined alignment in which the individual conductors of the cable are parallel with the planes of the blades of the cutter and accurately spaced therebetween. In accordance with theprinciples of the invention, the amount of rotation of the gang cutter may be selected to vary the lengths of the separating cuts in order to meet the requirements of a particular wiring application.

As a more specific aspect of the invention, special blades having circular cutting surfaces of less than 360 are provided in a staggered relationship, that is, with their termini radially displaced from one another in a manner whereby the separations of adjacent conductors are of progressively greater lengths enabling an angular axis of bending to be formed to enable parallel angular bends of the individual conductors to be made with facility in the plane of the ribbon cable.

3314,3211 Patented Apr. 18, 1967 "ice Absent angular separations of the type effected by the new apparatus, the parallel bending of the individual conductors in the plane of the ribbon would be most difficult, since the bending of each wire at the termination of the separating slit interferes with the parallel bending of the adjacent wire. By offsetting the terminations of the separating cuts and thereby offsetting the apices of the angles formed by each wire along an angular axis of bending, this interference is eliminated. Thus the parallel bending of all the wires in a ribbon cable may be accomplished with ease when it is slit in the new manner.

These and other advantageous features of the new invention may be better understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a plan view of the new and improved slitting apparatus embodying the principles of the present invention;

FIG. 2 is a crosssectional, elevational view taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged, fragmentary, cross-sectional view showing details of the ribbon cable slitting;

FIG. 4 is a crosssectional view of the new and improved apparatus taken alongline 4-4 of FIG. 2;

FIG. 5 is a side elevational view of the cutting blades of the apparatus showing the staggered relation thereof;

FIG. 6 is a fragmentary, elevational view showing details of construction of the means employed to vary the slitting stroke of the apparatus;

FIG. 7 is an enlarged, fragmentary, cross-sectional view of the gang cutter showing details of construction thereof;

FIG. 8 is a plan view of a ribbon cable having its wires separated along uniform lengths thereof; and

FIGS. 9 and 10 are plan views showing ribbon cables separated along progressively longer lengths thereof to accommodate angular bends of the individual conductors in the planes of the ribbons.

Referring now to FIGS. 1 and 2, the new ribbon cable slitter is generally indicated by reference numeral 10 and includes a flat base plate 11 to which vertical, parallel side walls 12 and 13 are welded or otherwise suitably secured. Transversely extending horizontal rod members 14, 15 maintain the spacing between the walls and are fastened thereto by studs 16. Journaled in the side walls 12, 13 in spaced bearing openings 17 is a rotatable drive shaft 19. A non-rotatable drum support shaft 20 having an eccentric central portion 23 is supported parallel to the shaft 19 in openings 18 formed in the walls 12, 13.

A gang cutter assembly 21 is secured to the shaft 19 to rotate therewith, while a ribbon support drum 22 is rotatably mounted on the central portion 23 of the shaft 21) to rotate thereabout. The cutter assembly 21 is of a width substantially equal to the widest ribbon size to be handled. For example, when slitting a ribbon cable comprised of forty conductors having a center to center spacing of .050 inch, the distance between the walls 31 of the cutter assembly will be sli htly greater than 2.00 inches. A gang of cutter blades 25 is spaced by annular spacing discs 26, 27 so as to be precisely alignable between adjacent conductors C of a ribbon to be separated. As shown, the blades 25 are .of uniform width, therefore the endmost spacers 27 are of slightly greater width than the inner spacers 26 which are of uniform lesser width. The assembly of blades and spacers is clamped between the cutter walls 31 which are, in turn, clamped between a bushing 48 fixed to the shaft 19 and a lock nut 49 threaded to the shaft. It should be understood that the combined width of an inner spacer 26 and the body of the cutting blade 25 is precisely equal to the center to center conductor spacing of the ribbon cable to be separated.

The individual cutter blades are made of steel discs, the edges of which are ground down to a fine knife edge 30 having a wedge shaped cross section, as shown best in FIG. 3. As will be understood, the length of the separating cut, the stroke of the apparatus, is a function of the blade diameter and the amount of rotation thereof. Accordingly, the stroke may be shortened or lengthened by adjusting the extent of the rotation of the cutters, as will be explained hereinafter.

Specifically, the support drum 22 is rotatably supported on the central offset portion 23 of the shaft and includes a series of annular channels 32 on the face thereof. The channels generally conform with the sinuous configuration defined by the outer surfaces of the ribbon cable and are of a depth slightly less than one-half the thickness of the cable to be separated (FIG. 3). In other words, the depth of the channels is slightly less than the radius of the sheath of insulation I enveloping each of the conductors C. Accordingly, flats or anvil surfaces 33 are defined between each of the channels, as shown best in FIG. 3, which drum surfaces cooperate with cutter blades to define a cutting nip 34. It should be noted that the cutter walls 31 project beyond the periphery of the drum 22 in order to maintain control over the endrnost conductors of a cable which is being slit.

As will be understood, the knife edges of the cutter blades are arranged to extend down and through the insulation of a ribbon cable inserted into the nip 34 at points precisely intermediate adjacent conductors to effect a clean separation thereof. Furthermore and as an im portant aspect of the invention, rotation of the cutters will cause the ribbon :cable to be driven therepast by virtue of the frictional engagement of the sides of the wedge shaped blades with the insulation enveloping the individual conductors in the nature of a driven sheave. Thus, rotation of the blades will advance a ribbon cable which has been inserted into the nip 34 over the support drum 22 while separating the end portions of adjacent conductors along the length of displacement (FIG. 3). In accordance with a specific aspect of the invention, the spaced relationship between the gang cutter 21 and the support drum 22, that is, the depth of the nip 34, may be easily adjusted by turning the shaft 26 with a screwdriver (in slot 24) to raise or lower the axis of the central portions 23, about which the drum rotates, with respect to the cutter in order to achieve the aforementioned sheavelike advance of an inserted ribbon cable. The desired nip size is fixed by locking the shaft 20 to the wall 12 with a stud 28 and lock washer 29.

In accordance with the invention, operation of the ;litter 10 may be manual or electric. The cutter assem- Jly may be bi-directionally rotated by a crank handle ippropriately aflixed to the end of the drive shaft 19 or hrough a reversible electric motor 41 secured to side wall [3 and adapted to drive the shaft 19 through a pinion 43 tnd a gear 45, suitably aflixed to the shaft 19. The length if separation of the ends of a ribbon cable, the stroke )f the apparatus, is controlled by the degree of rotation if the cutting blades after the ribbon cable has come in ontact therewith.

When the apparatus is to be manually driven, a conrol arm 35 is affixed to an outer end of the driving shaft 9 to limit the rotation thereof between a predetermined tarting point established by a first pin 36 fixedly mounted 1 the wall 12 and a second pin 37 spaced from the startig pin 36 in the path of the arm 35, as shown in FIG. 2. will be understood that the cutting stroke of the appaitLlS will be directly proportional to the angular spacing etween the pins 36, 37. To vary the stroke of the aparatus, it is merely necessary to change the position of le adjustable pin 37 which is threaded into one of a :ries of tapped holes 38, as may be readily understood. hen the shaft 19 is driven by the motor 41, a motor reversing switch 44 may be substituted for the second pin 37 and a motor cut-off switch 46 may be substituted for the first pin 36. For motorized operation, a motor energizing or on switch 47 is mounted on the slitter 10 in readily accessible and convenient location.

In accordance with the invention, a wire guide assembly 50, mounted by brackets to the walls 12, 13 of the slitter mechanism 10, provides controlled, guided support for a cable to ensure its entry into the nip 34 in a properly aligned relation with the blades 25. The proper alignment of the ribbon cables in the nip 34 is imperative, as should be appreciated, since the ribbon cables are of unusually small dimensions and a misalignment will tend to damage the cable and jam the slitting mechanism. As shown, the guide assembly includes a flat base plate 51 disposed at the level of the nip 34 and generally tangent with the cutting blades 25 and the support drum 22. A guide bar 52, having a guiding surface 53 in the plane of the inner surface of the righthand cutter wall 31, is mounted on the plate 51, as shown best in FIG. 1. Fine adjustment of the guide bar 52 may be had by virtue of the slots 56 formed therein and the screws 57 securing it to the guide plate. A slide 60 is also mounted on the guide plate 51 in slide blocks 58, which slide is transversely adjustable by a screw jack 59 to accommodate ribbon cables of varying widths. The free end 61 of the slide maintains the cable in alignment with the guiding surface 53.

As will be understood, when the end wire 54 of a ribbon cable 55 is in alignment, the remaining wires will also be in alignment, since the cable itself is maintained parallel with the planes of the blades between the guiding surfaces 53, 61. As shown, the guide plate 51 has an adjustable extension plate 62, mounted for fine adjustment thereon by screws 61, which projects towards the nip 34 and terminates immediately short thereof. The described arrangement provides a maximum of controlled support for the cable prior to its slitting.

Operation of the new and improved slitting mechanism It is extremely simple and highly eificient. With the guiding surfaces adjusted for width of the cable to be slit, it is only necessary for an operator to slide the cable 55 along the guide plate 51 and into the nip 34, thereafter to rotate the shaft 19 clockwise for the predetermined slitting stroke established by the spacing of the pins 36, 37, and finally to withdraw the cable from the nip by reversing the shaft rotation. With an electric drive, it is only necessary for the operator to insert the cable into the nip and start the motor 41 by depressing the on button 47 (which advantageously may be mounted on the guide bar 52, as shown in FIG. 1) to cause the motor to rotate in the clockwise direction until it is reversed by the action of the control arm 35 tripping the switch 44. The separated ends of the cable will then be driven out of the apparatus by the reverse rotation of the motor which will be automatically de-energized by the switch 46 upon the return of the control arm 35 to the starting position.

As a more specific aspect of the invention, separation of the wires of a cable may be effected along progressively longer lengths to form an angular axis of bending BB, as shown in FIG. 9, to permit the individual conductors to be sharply bent in the plane of the ribbon when making terminal connections. This is effected in accordance with the inventive principles by removing cutting surfaces from the blades 25 to provide each one with a clearly defined terminal portion 70, as shown in FIGS. 4 and 5, beyond which is a non-effective portion 73. By staggering the termini of the blades with respect to one another, as shown in FIG. 5, to provide differing effective cutting lengths for each blade 25 as measured from the nip 34 to the terminal portion, a differential separation of the conductors definitive of an angular axis of bending will be readily effected. As the cable is drawn into and past the nip 34, each cutter 25 will effect a slit of a differcut length, determined by the total circumferential displacement of its terminal portion 70 from the nip (the starting point of its cutting action).

As shown in FIGS. 4 and 7, the sides of the spacers 26, 27 may be beveled to form radial grooves 71 into which detents 72 formed on both sides of the cutter blades 25 may be inserted. This facilitates the establishment of the above described staggered relationship of the blades, enabling any desired angular relationship be tween blades to be quickly made. Thus, for example, the axis of bending BB of the cable may be at an approximate 45 angle to facilitate bending the conductors of the ribbon cable, as shown in FIG. 9, or it may be at a more acute angle for the bending arrangement illustrated in FIG. 10. The control arm 35, itself, is adapted to be fixed to the shaft 19 through its collar 35a and set screw 75, in any desired position. As will be understood, by appropriately relating the control arm 35 and the termini 79 of the blades 25 to the nip 34, the apparatus may be used either for straight separations of the type shown in FIG. 8 (in which the separating stroke ends before the non-effective portions 73 of the blades reach the nip 34) or for angular separations of the type shown in FIGS. 9 and 10 (in which the separating stroke includes the rotation of the non-effective portions 73 through the nip 34).

It will be appreciated that the new tool may easily be adjusted to accommodate cables having larger or smaller wire sizes by substituting a support drum having channels accommodative of the wire size for the support drum 22 and by substituting spacers for the spacers 26, 27 to provide the requisite center to center spacing.

The new and improved slitting mechanism enables the ends of ribbon cables to be separated in a rapid and efficient manner. The adjustable guide assembly provides the proper alignment of a ribbon cable with the gang cutter to effect uniform and clean separations of the individual conductors without any wire damage. Moreover, the provision of blades having predetermined non-effective portions, which blades may be quickly and easily arranged in a staggered relationship, enables ribbon cables to be quickly and efficiently separated along selected angular axes of bending.

It should be understood that the specific apparatus herein illustrated and described is intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.

I claim:

1. Apparatus for simultaneously separating the ends of a plurality of longitudinal electric conductors which are independently enveloped by insulation and have a predetermined center to center spacing, which conductors are bonded together in side-by-side relationship in the form of a ribbon having a predetermined thickness, comprising (a) a rotatable shaft means,

(b) a plurality of circular cutting blades mounted on said shaft means,

(c) means spacing said blades axially along said shaft at said predetermined center to center spacing,

(d) selectively operable means rotating said shaft means for predetermined angular displacements,

(e) rotatable supporting drum means cooperating with said rotatable cutting blades to support the lower surface portions of said ribbon and with said blades to define a slitting nip,

(f) guide means located adjacent said nip and adapted to align a ribbon of bonded conductors with said nip in a manner whereby the planes of said blades are located intermediately of and parallel to said conductors,

(g) means limiting the rotation of said cutting blades 7 to less than one full revolution,

(h) whereby rotation of at least one of said rotatable means in a predetermined direction will draw said ribbon through said nip to effect a predetermined separation of said insulated conductors and rotation of said at least one rotatable means in an opposite direction will withdraw the separated ends of the ribbon from said nip.

2. Apparatus for simultaneously separating the ends of a plurality of longitudinal electrical conductors which are independently enveloped by insulation and have a predetermined center to center spacing, which conductors are bonded together in side-by-side relationship in the form of a ribbon having a predetermined thickness, comprising (a) a rotatable shaft means,

(b) a plurality of circular cutting blades mounted on said shaft means,

(0) said cutter blades are of circumferential lengths of less than 360 and include trailing edge portions which are absent a cutting edge,

(d) said trailing edge portions of said blades are arranged in a predetermined staggered relationship, (e) means spacing said blades axially along said shaft at said predetermined center to center spacing, (f) selectively operable means rotating said shaft means for predetermined angular displacements,

(g) :rotatable supporting drum means cooperating with said rotatable cutting blades to support the lower surface portions of said ribbon and with said blades to define a slitting nip,

(h) guide means located adjacent said nip and adapted to align a ribbon of bonded conductors with said nip in a manner whereby the planes of said blades are located intermediately of and parallel to said conductors,

(i) whereby rotation of at least one of said rotatable means in a predetermined direction will draw said ribbon through said nip to effect a predetermined separation of said insulated conductors along varying lengths accommodative of the subsequent bending of each of said conductors in the plane of the ribbon at a predetermined angle with respect to the normal longitudinal axis of the ribbon and rotation of said at least one rotatable means in an opposite direction will withdraw the separated ends of the ribbon from said nip.

3. Apparatus in accordance with claim 2, in which (a) detent means are formed on the sides of said cutting blades,

(b) radial grooves are formed on the sides of said spacing means,

(c) whereby said detents may be inserted into said grooves to establish said predetermined staggered relationships between the trailing edge portions of said cutting blades.

4. Apparatus in accordance with claim 3, in which (a) said cutting blades are driven,

(b) a drum shaft supports said drum means for rotation thereabout,

(c) said drum shaft includes eccentric means to adjust selectively the axis of rotation of said drum means with respect to said cutting blades, thereby varying the size of said nip.

5. A tool for simultaneously separating independently insulated conductors of a ribbon cable, which comprises (a) a rotatable drive shaft,

(b) a plurality of circular cutting blades extending radially therefrom and spaced axially therealong at predetermined intervals equal to the center spacing of the conductors comprising said ribbon cable,

(c) supporting drum means including annular recesses formed on the surface thereof at said predetermined intervals,

((1) means mounting said drive shaft for rotation about a predetermined axis,

(e) means mounting said support drum for rotation about a predetermined axis,

(f) drive means for effecting the rotation of said drive shaft,

(g) adjust-able stop means for selectively limiting the angular travel of said drive shaft,

(h) ribbon guide means adjacent said drums for guiding a ribbon into a nip defined between said drum means and said blades in a predetermined path in which each of said cutting blades is centered between adjacent ones of said insulated conductors,

(i) whereby upon the rotation of said drive means said insulated conductors of the ribbon cable will be drawn through said nip and separated from one another,

6. A tool in accordance with claim 5, in which (a) said means mounting said drive shaft includes a wall,

(b) a radially extending control arm is mounted on said drive shaft adjacent said wall, 7

(c) said stop means includes a pin adapted to be supported by said wall in the path of said arm in one of a plurality of positions.

7. A tool in accordance with claim 6, in which (a) said cutting blades include non-effective portions,

(b) said non-effective portions are offset from one another in a manner providing progressively longer separations of adjacent conductors when said offset portions are driven past said nip.

8. A tool in accordance with claim 6, in which (a) a pair of guide walls are mounted on said shaft and spaced apart a distance substantially equal to the Width of the ribbon cable be slit,

(b) said guide Walls project radially beyond the periphery of said supporting drum means,

(c) said walls have inner guide surfaces adapted to control the edges of a ribbon cable being slit in its advance toward and through the nip.

9. A tool in accordance with claim 8, in which (a) said ribbon guide means includes a pair of spaced parallel surfaces,

(b) said spaced parallel surfaces and said inner guide surfaces are coplanar and parallel with the planes of said cutting blades.

It). A tool in accordance with claim 5, in which (a) said drive means includes a reversible electric motor,

(b) said means mounting said drive shaft includes a wall,

(c) a radially extending control arm is mounted on said drive shaft adjacent said wall,

(cl) said adjustable stop means includes a motor reversing switch actuable by said control arm as it rotates in a first predetermined direction to reverse the direction of said motor.

11. A tool in accordance with claim 10, in which (a) said motor may be selectively energized by a motor on switch means,

(b) said motor is adapted to be de-energized by a motor off switch means disposed at a predetermined point in the path of said control arm.

12. A tool in accordance with claim 11, in which a (a) the location of one of said motor off and said motor reversing switches relative to the other may be selectively adjusted,

(b) whereby the angular travel of said drive shaft is directly determined by the angular spacing between said motor off and motor reversing switches.

References Qited by the Examiner UNITED STATES PATENTS ANDREW R. JUHASZ, Primary Examiner. 

1. APPARATUS FOR SIMULTANEOUSLY SEPARATING THE ENDS OF A PLURALITY OF LONGITUDINAL ELECTRIC CONDUCTORS WHICH ARE INDEPENDENTLY ENVELOPED BY INSULATION AND HAVE A PREDETERMINED CENTER TO CENTER SPACING, WHICH CONDUCTORS ARE BONDED TOGETHER IN SIDE-BY-SIDE RELATIONSHIP IN THE FORM OF A RIBBON HAVING A PREDETERMINED THICKNESS, COMPRISING (A) A ROTATABLE SHAFT MEANS, (B) A PLURALITY OF CIRCULAR CUTTING BLADES MOUNTED ON SAID SHAFT MEANS, (C) MEANS SPACING SAID BLADES AXIALLY ALONG SAID SHAFT AT SAID PREDETERMINED CENTER TO CENTER SPACING, (D) SELECTIVELY OPERABLE MEANS ROTATING SAID SHAFT MEANS FOR PREDETERMINED ANGULAR DISPLACEMENTS, (E) ROTATABLE SUPPORTING DRUM MEANS COOPERATING WITH SAID ROTATABLE CUTTING BLADES TO SUPPORT THE LOWER SURFACE PORTIONS OF SAID RIBBON AND WITH SAID BLADES TO DEFINE A SLITTING NIP, (F) GUIDE MEANS LOCATED ADJACENT SAID NIP AND ADAPTED TO ALIGN A RIBBON OF BONDED CONDUCTORS WITH SAID NIP IN A MANNER WHEREBY THE PLANES OF SAID BLADES ARE LOCATED INTERMEDIATELY OF AND PARALLEL TO SAID CONDUCTORS, (G) MEANS LIMITING THE ROTATION OF SAID CUTTING BLADES TO LESS THAN ONE FULL REVOLUTION, (H) WHEREBY ROTATION OF AT LEAST ONE OF SAID ROTATABLE MEANS IN A PREDETERMINED DIRECTION WILL DRAW SAID RIBBON THROUGH SAID NIP TO EFFECT A PREDETERMINED SEPARATION OF SAID INSULATED CONDUCTORS AND ROTATION OF SAID AT LEAST ONE ROTATABLE MEANS IN AN OPPOSITE DIRECTION WILL WITHDRAW THE SEPARATED ENDS OF THE RIBBON FROM SAID NIP. 